Quic.Recovery (elixir_quic v0.16.7)

Explicit-time QUIC packet-number spaces and loss recovery state.

Packet numbers are allocated by reserve/4 and are never reused. A packet moves through :reserved, :queued, :sent, then :acked, :lost, or :failed. ACKs received before a local send receipt are retained as a bounded pending acknowledgement and resolved when the receipt arrives.

Summary

Types

initial_state()

t()

Functions

arm(state)

Recompute the next deadline from actual sent packets, without advancing time.

discard_space(state, space)

Discard an encryption space's outstanding work while preserving allocated packet numbers.

local_send(state, space, number, arg4, at)

new(opts \\ [])

note_received(state, space, number)

Record an authenticated packet number received in a packet-number space.

on_time(state, now)

pto_duration(state)

Current probe timeout duration in microseconds, before PTO backoff.

receive_ack(state, space, ack, at)

reserve(state, space, metadata \\ %{}, bytes \\ 0)

retire_space(state, space)

Permanently retire Initial/Handshake recovery, preserving the next packet number.

timer_expired?(recovery, token, now)

transition(state, space, number, status)

Types

initial_state()

@type initial_state() :: %Quic.Recovery{
  congestion: %Quic.Congestion.NewReno{
    acked_bytes: 0,
    bytes_in_flight: 0,
    cwnd: term(),
    max_datagram_size: term(),
    mss: number(),
    ssthresh: term()
  },
  deadline: nil,
  max_ack_ranges: term(),
  max_sent_packets: term(),
  rtt: %Quic.Recovery.RTT{
    ack_delay_exponent: term(),
    latest: nil,
    max_ack_delay: term(),
    min: nil,
    pto_count: 0,
    smoothed: nil,
    variance: nil
  },
  spaces: map(),
  timer_generation: 0
}

t()

@type t() :: %Quic.Recovery{
  congestion: term(),
  deadline: term(),
  max_ack_ranges: term(),
  max_sent_packets: term(),
  rtt: term(),
  spaces: term(),
  timer_generation: term()
}

Functions

arm(state)

Recompute the next deadline from actual sent packets, without advancing time.

discard_space(state, space)

Discard an encryption space's outstanding work while preserving allocated packet numbers.

local_send(state, space, number, arg4, at)

@spec local_send(t(), atom(), non_neg_integer(), :ok | {:error, term()}, integer()) ::
  {:ok, t(), [atom()]} | {:error, atom()}

new(opts \\ [])

@spec new(keyword()) :: initial_state()

note_received(state, space, number)

@spec note_received(t(), atom(), non_neg_integer()) :: {:ok, t()} | {:error, atom()}

Record an authenticated packet number received in a packet-number space.

on_time(state, now)

@spec on_time(t(), integer()) :: {:ok, t(), map()}

pto_duration(state)

@spec pto_duration(t()) :: pos_integer()

Current probe timeout duration in microseconds, before PTO backoff.

receive_ack(state, space, ack, at)

@spec receive_ack(t(), atom(), map(), integer()) ::
  {:ok, t(), map()} | {:error, atom()}

reserve(state, space, metadata \\ %{}, bytes \\ 0)

@spec reserve(t(), atom(), map(), non_neg_integer()) ::
  {:ok, t(), Quic.Recovery.Packet.t()} | {:error, atom()}

retire_space(state, space)

@spec retire_space(t(), :initial | :handshake) :: t()

Permanently retire Initial/Handshake recovery, preserving the next packet number.

timer_expired?(recovery, token, now)

@spec timer_expired?(t(), non_neg_integer(), integer()) :: boolean()

transition(state, space, number, status)

@spec transition(t(), atom(), non_neg_integer(), atom()) ::
  {:ok, t()} | {:error, atom()}